A catastrophic humanitarian situation is unfolding in northeast Nigeria, where Boko Haram Islamists have displaced nearly 2 million people since 2013, the U.N. refugee agency said Friday.

The U.N. High Commissioner for Refugees said the extent of the suffering to which Boko Haram victims have been subjected was only now becoming visible. It said government forces' advances into the Islamist group’s previous stronghold in northeast Nigeria had exposed the destitution of the displaced population.

UNHCR spokesman Adrian Edwards said aid agencies could not move around freely amid the continuing military campaign. He said that the situation in the region remained dangerous and volatile and that it was impossible to go to some areas without a military escort.

Edwards said the suffering in Borno and Yobe states was shocking. He cited numerous reports of human rights violations, including deaths, sexual violence, disappearances, forced recruitment, forced religious conversions and attacks on civilian sites.

He said population of Bama, the largest city in Borno after the capital, Maiduguri, had been deeply traumatized. Many of the displaced are women, children and the elderly, he said.

“We have seen adults so exhausted they are unable to move, children with swollen faces and hollow eyes and other clear indications of acute malnutrition," Edwards said. "Many also show signs of severe trauma. We have people screaming at night. We have aggression among children. People complain about a lack of food and water.”

Regional crisis

Edwards said that with the lack of security along the borders with Niger, Chad and northern Cameroon, the insurgency in northeast Nigeria had turned into a vast regional crisis, with immense suffering among both the Nigerian refugees and internally displaced nationals.

“One consequence is that Nigerian refugees are fleeing back into their own country, into one of the most catastrophic areas as far as humanitarian needs are concerned that we are seeing at the moment," he said. "So, it is moving, it is dynamic. It is very difficult, and the insecurity, as I said, it is making it a very tough job indeed, getting these people the help that they desperately need.”

The UNHCR is scaling up its operations to provide lifesaving assistance to nearly 500,000 people. The World Food Program and U.N. children’s fund said they were trying to reach more than 700,000 people in desperate need.

The beneficiaries are concentrated in 10 newly liberated local government areas in Borno state, but the U.N. agencies said the thousands of refugees who have returned to Nigeria from the three Lake Chad Basin neighbors also urgently needed care.